The agreement underscores the resilience of Tehran’s alliance with Damascus, despite overtures to the US in the past year, and allows Iran to project the image of a unified front in the face of threats of sanctions and military strikes.

Posturing aside, however, analysts say that Syria appears reluctant to jeopardize its newly increased respectability on the world stage, for which it struggled after years of international isolation.

The defense agreement came about at Iran’s initiative says Murhaf Jouejati, professor at the National Defense University in Washington. "The Syrians were reluctant to use the clear language [on mutual assistance] that Iran wanted to use,” he said.

No details of the agreement made public

The agreement was announced on Dec. 11 by the official Iranian channel Press TV and followed a three-day visit of Defense Minister Vahidi to Damascus. No details of the text have been made public, but some observers say that the exact contents of the agreement matters less than its political meaning.

While Syria is “persuaded” that the Iranian nuclear program is for civilian purposes, says Prof. Jouejati, Western states suspect Iran of using the program to build a nuclear weapon – a claim the Iranian authorities have always denied.

Syria has yet to see benefits of thaw with US

Mr. Harling argues that ”frequent delegations traveling between the two countries are meant to signal that Syria will not forsake its alliance with Iran, even as it broadens its strategic portfolio through improved diplomatic relations with the West, Turkey and, to a lesser extent, Saudi Arabia.”

But, whereas the rapprochement with France has included a series of high-level visits Syria has yet to see benefits from the thaw with the US. Sanctions remain in force, and an American ambassador has yet to be appointed to Damascus, nearly a year into President Barack Obama’s first term. Meanwhile, peace negotiations with Israel over the Golan Heights remain elusive.

This stance, Harling adds, strengthens Syria's hand in discussions with the US and possible renewed talks with Israel.

Jouejati says Syria “will not forgo its alliance with Iran,” unless it obtains “iron-clad guarantees that it is going to recover the Golan Heights.”